TY - CHAP M1 - Book, Section TI - Assessing the Circulation: Oximetry, Indicator Dilution, and Pulse Contour Analysis A1 - Pinsky, Michael R. A2 - Hall, Jesse B. A2 - Schmidt, Gregory A. A2 - Kress, John P. Y1 - 2015 N1 - T2 - Principles of Critical Care, 4e AB - No hemodynamic monitoring device will improve patient outcome unless coupled to a treatment, which itself improves outcome.Low venous oxygen saturations need not mean circulatory shock but do imply circulatory stress, as they may occur in the setting of hypoxemia, anemia, exercise, as well as circulatory shock.There is no “normal” cardiac output, only one that is adequate or inadequate to meet the metabolic demands of the body. Thus, targeting a specific cardiac output value without reference to metabolic need, or oxygen-carrying capacity of the blood, is dangerous.Cardiac output is estimated, not measured, by all devices routinely used in bedside monitoring (though we shall call it measured in this text).Cardiac output estimates using arterial pulse pressure contour analysis cannot be interchanged among devices and all suffer to a greater or lesser extent by changes of peripheral vasomotor tone commonly seen in the critically ill.Since metabolic demands can vary rapidly, continuous or frequent measures of cardiac output are preferred to single or widely spaced individual measures.Integrating several physiologic variables in the assessment of the adequacy of the circulation usually gives a clearer picture than just looking at one variable.Integrating cardiac output with other measures, like venous oxygen saturation, can be very helpful in defining the adequacy of blood flow. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accesssurgery.mhmedical.com/content.aspx?aid=1107716750 ER -